Electrical controlling device



D. J. BURNS.

ELECTRICAL CONTROLLING DEVICE.

APPUCATION HLED JUNE H. was.

Patented May 16, 1922.

' INVENTOR UNITED STATES PATENT OFFICE.

DAWSON J'A'BEZ BURNS, OF BRONXVILLE, NEW YORK, ASSIG-NOR TO WARD LEONARD ELECTRIC COMPANY, A CORPGRATION OF NERV YORK.

ELECTRICAL CONTROLLING DEVICE.

Application filed. June 14:,

T 0 all w 7mm it may concern Be it known that I, Dawson J. BUnNs, a citizen of the United States. residing at Bronxville, in the county of W'estchester and State of New York, have invented certain new and useful Improvements in Electrical Controlling Devices, of which the following is a specification.

The principal objects of my invention are to provide a new and improved rheostat and advantageous features of construction that may be used in connection therewith. Another object of my invention is to provide a small adjustable resistance controller that shall be simple and inexpensive to manuifacture and rugged and efficient in service. These and other objects of my invention will become apparent on consideration of a specific example thereof, which is shown in some detail in the accompanying drawings and. described in the following specification. It will be understood that modifications can be made within the scope of the invention.

Referring to the drawings, Figure 1 is a vertical section of an electric motor fan base with my improved controller incorpor ate-d therein.

Fig 2 is a view of the controller looking in the direction of the arrow 2 of Fig. 1.

Fig. 3 is a view of the controller as it would appear it removed. from the fan base and viewed in the direction of the arrow of Fig. 1. i

Fig. 4: is a. fragmentary detail section on the line 4r4: of Fig. 3.

The fan base 11 has a hole 12 in its side and within the base 11 adjacent to this hole 12 is the insulating support comprising the earthenware tube 1% with the integral flange or head 13 at one end. The head 13 carries two lugs 15, each with a hole 16, and there are registering holes 17 in the base shell 11 through. which extend the bolts 18 clamping the insulating frame lit--14 in rigid relation to the pedestal 11..

Numerous turns of line resistance wire spaced apart are wound on the tube 14 as indicated by the numeral 19. The stranded conductors 20 and 22 are fastened around. the ends with conductive connection to the resistance conductor 19, and the branches and 28 serve as end terminals or leads.

The intermediate stranded conductor 21 has an intermediate lead or tap 26 extending therefrom. The end lead 23 is passed throu Specification of Letters Patent.

Patented May 16, 1922.

1919. Serial No. 304,259.

two holes 48 and. 49 in the flange 13 havinga portion 24 bent around between them. in the process of assembly a head 24' is placed. over this portion 24: of the conductor and flattened down against the head 13 and soldered to the stranded conductor 2st. This flattened bead 24 serves as a contact terminal as will be pointed out more fully later. Similarly the intermediate tap 26 leads to the head 27 and the end conductor 28 to the bead 29. The resistance wire 19 and stranded conductors and connections are coated, as shown in the drawings, with an insulating coating 47, such as vitreous enamel material, and the tubular unit is then placed. in. a furnace andbaked or fired in the usual manner.

A'lznob of insulating material 30 has a recess 31 leaving a shoulder 32 at the. bottom around the axial hole 50. The bolt 33 eX- tending through the hole 50 and along the axis of the tube 14 has a collar 34: and a contact arm 35 assembled therewith in the relation. shown in Fig. 1.. The knob 30 has a notch 36 extending diametrically across its inner end and the contact arm 35'lies partly in this notch 36 so that the arm 35 is. constrained to rotate with the knob 30. The bolt 33 is screw-threaded along its length and the nut 3'? terms an abutment which is drawn tightly against the head 13. At the other end are the insulating mica pieces 38, nut 39, conductor 40 between washers and the outer clamping nut 42. The conductor 40 leads at 4:1 to one terminal of the tan motor, the return conductor therefrom being designated 43. The pre- 'viously mentioned terminal conductor 23 after passing through the head 24: has the part twisted with the part 23 and then the part 25 continues and at 44 the conductors 25 and 43 are knotted together and pass through the bushing s5, and outside they are designated as 16. The knot a l prevents pulling the conductors 25 and 43 through the hole in the bushing 45.

it will be seen that of the two conductors to leading to the fan, one is extended at 43 directly to the motor and the return conductor ll makes electrical contact with the screw-threaded shaft 33 and thence with the contact arm 35. When the arm 35 is in the position shown in Fig. 3, the circuit is open. To start the tan motor the knob 30 will be rotated clockwise as viewed in Fig. When the arm 35 engages the contact 29, the circuit will be closed through lead 28, thence through all the resistance winding 19 to lead 23, through contact 24 and conductor 25 back to the knot 44:.

A further rotation of the knob 30 in the clockwise direction will bring the arm 35 in engagement with the bead 27 and the circuit will be the same as before, except that in stead of going from contact 29 through end conductor 28 and all the resistance on the tube 14:, it will go through contact 27, intermediate tap 26, and only that portion of the resistance between tap 26 and end conductor 23.

A further rotation of the knob 30 in the clockwise direction as viewed in Fig. 3 will bring the arm 35 in contact with the contact 24. The circuit will then go directly from the arm 35 to the conductor 25 without the interposition of any of the resistance c011- ductor 19; this will be the full running adjustment of the rheostat.

It will be seen that the shaft 33 is stationary. The nut 37 will be adjusted so that the sleeve 34, arm and knob 30 will turn freely thereon, the nut 37 being tight against the head 13. The transverse slot 36 obliges the arm 35 to rotate with the knob 30.

The/contact terminals 224:, 27 and 29 are exceedingly simple and inexpensive, but at the same time entirely serviceable and convenient.

It will be seen that the end of the contact arm 35 is bent a little in a transverse direction as appears in Fig. 2. The arm 35 is of spring metal strip and it will be apparent that its shape gives it a fairly definite stop position in exact registry with one of the beads 2 L, 2'? or 29. In rotating the tube 30 between the thumb and linger, these positions will readily be noticed and the knob can be turned to the proper adjustment for any one of them desired.

I claim 1. In combination, a tubular resistance unit with end leads and an intermediate tap, an insulating support at one end thereof, with said end leads and tap snubbed around portions thereof to form contact terminals and a pivoted switch arm to engage said terminals.

2. In combination, a tubular resistance unit with leads therefrom, an insulating support at one end thereof, with said leads snubbed around portions thereof to form contact terminals, and a pivoted switch-arm to engage said terminals.

3. In combination, a tubular resistance unit and a support integral therewith, leads from said unit snubbed around portions of said support to form contact terminals, and a pivoted switch-arm to engage said terminals.

4. In combination, a tubular earthenware member comprising a flange at one end, a resistance conductor wound on said memher, with leads therefrom snubbed around portions of said flange to serve as contact terminals, and a pivoted switch arm to engage said terminals.

5. In combination, a tubular support of insulatingmaterial with a flange at one end, a resistance conductor wound on said support, leads from said conductor snubbed around portions of said flange, a shaft in the tubular member, a handle rotatably mounted on said shaft, and a switch-arm carried by said handle and adapted to engage said terminals.

6. In combination, a tubular earthenware member with an integral flange at one end, a resistance conductor wound on the tubular part, contact terminals on said flange, leads connecting said resistance conductor with said terminals and a switch-arm pivoted at the axis of the tube and adapted to engage said terminals.

7. In combination, a tubular enai'neled resistance unit, with leads therefrom. a sector of insulating material at one end thereof with its center on the tubular axis, contact terminals on the sector connected with said leads, a shaft fixed at the axis of the tube and a switch-arm rotatably mounted on said shaft and adapted to engage said terminals.

8. In combination, a tubular earthenware support, a flange integral therewith, a resistance conductor on the tubular support, pairs of holes through said flange, leads from said conductor snubbed through and back in the pairs of holes to form contact terminals, and a pivoted switch-arn'i adapted to engage said terminals.

9. In combination, a tubular enameled re sistance unit, leads therefrom, corresponding contact terminals arranged around the axis of the unit, a shaft fixed in said axis and a switch-arm rotatably mounted on said shaft to engage said terminals.

10. In a rheostat, an insulating support, a resistance conductor thereon, contact terminals arranged 011 an arc of a circle, leads therefrom to said conductor, a shaft fixed at the center of the circle, a knob rotatably mounted. on said shaft, said knob having a diametral notch, and a switch-arm lying in said diametral notch, so as to be rotated by the turning of said knob.

11. In combination, a support of insulating material having two holes therethrough, a flexible electrical conductor looped in and out through said holes and forming a contact terminal where it bends across between them, and a movable switch member to en gage said terminal.

12. In combination, a support of insulating material having two holes therethrough, a metallic bead, a flexible electrical conductor looped in through. one hole then through the bead and then back through the other hole, so as to hold the bead betweenthe two holes to form a contact terminal and a movable switch member to engage said terminal.

member and a sector at one end integral therewith, said sector having its center at the tubular axis, a resistance conductor on the tubular part, contact termmals on the sector part, leads between said resistance conductor and said terminals, and a switch arm pivoted at the tubular aXis and engaging said terminals.

15. In a rheostat, an insulating support, a resistance conductor carried thereby, a set of associated contact terminals carried by said support and arranged in an arc of a circle, a shaft fixed on said support at the center of the circle, a knob rotatably mounted on said shaft and having a diametral notch, a collar around the shaft, a leaf spring switch arm with two holes and bent nearly double between said holes, said shaft passing through said holes with the collar between and the part adjacent to one hole lying in said notch, and two spaced abutments on said shaft between which said knob, collar and switch arm are located.

16. In combination, a support of insulat ing material having a hole therethrough, a flexible electrical conductor passed through said hole and bent abruptly aside adjacent thereto to form a contact terminal, and a movable switch member to engage said terminal.

17. In combination, a support of insulating material, a flexible electrical conductor bent abruptly around a portion of said support to form a contact terminal, and a mov-.

able switch member to engage said terminal.

18.111 combination, a tubular support of insulating material, a resistance conductor thereon, contact terminals arranged in an arc of a circle around the tubular axis at one end,

a shaft lying in the tubular axis and projecting at the end having said terminals, a head on said shaft at the same end, an abutment on said shaft at that end close to the support, a clamping nut at the opposite end, and a switch arm and handle on the shaft between the head and abutment and adapted to cooperate with said terminals.

19. A resistance unit comprising a tube of insulating material, a resistance element thereon, and contacts connected by leads with said resistance element, said tube of insulating material having integral therewith an insulating portion for supporting said contacts.

DAJVSON JABEZ BURNS. 

